Hammer mill construction



March 19, 1957 w. E. BERLING 2,785,865

HAMMER MILL CONSTRUCTION Filed April 15, 1953 2 Sheets-Sheet l #421 MHZ..5554 mm flrrok/vars.

March 19, 1957 w. E. BERLING HAMMER MILL CONSTRUCTION 2 Sheets-Sheet 2INVENTOR. Mum/1 E firm/A e flrraz/vzns,

Filed April 15, 1953 HAB/TMER MILL CONSTRUCTION William E. Berling,Indianapolis, Ind.

Application April 15, 1953, Serial No. 349,627

1 Claim. (Cl. 241-186) This invention relates to a hammer mill, and moreparticularly to one designed for custom grinding of a wide variety oimaterials.

Heretofore it has been necessary in connection with conventional hammermills to go to considerable trouble and efiort when it is desired tochange the degree of fineness of the material being ground. For example,in order to effect the change it has been necessary that a screen meshbe inserted. This is a time consuming undertaking, and as well involvesthe expense of having screens of different mesh on hand. It is theprimary object of this invention to eliminate this loss of time andexpense. The object is accomplished through the provision of a hammermill which can readily and easily be adjusted to vary the degree offineness of the grind without stopping the mill and without changing thescreen. Furthermore, the change can be made by the operator from theoperating floor above the mill. It i thus unnecessary for him to climbdown into the pit in which the mills are customarily positioned.

it is a further object of the present invention to provide a mill inwhich both friable and non-friable mateterials can be ground withouthammer adjustment or change. This is accomplished through the provisionof three separate series of heavy crushing hammers, medium grindinghammers, and thin cutting hammers respectively, the series beingcharacterized by progressively smaller hammers from the inlet towardsthe outlet end. With this progressive reduction from heavy impacthammers to thin shear hammers, any grindable material or mixture ofmaterials can be efficiently ground regardless of their specificgravity.

It is a still further object of this invention to assure a cool, evengrind of the materials, thereby preserving their nutritional values. Ithas long been known that high temperatures destroy or at least reducethe nutritional values of materials, and the present invention isdesigned to avoid this occurrence. This is accomplished through theelimination of the screens and the provision of means which direct amoving stream of cool air through the mill. Provision is also made forreadily adjusting the air control, thereby making possible a moreprecise particle size control and classification.

A further advantage stemming from the air control means is the abilityto grind heat sensitive materials at higher capacity.

It is a still further object of the present invention to eliminate thegradual reduction in grinding capacity which characterizes conventionalmills because of the inevitable Wear of their screens. Materials areground in the present invention without forcing them through any screen.

it is an even further object of this invention to provide a mill of suchconstruction that it will withstand the rigors of the heaviest grindingwithout undue strain.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claim.

States Patent In the drawings:

Fig. 1 is a side elevation view of the invention with parts thereofshown in section.

Fig. 2 is a vertical section view thereof taken on lines 22 of Fig. 1 inthe direction of the arrows, with the feed table shown in sideelevation.

Fig. 3 is an enlarged view of relatively adjustable plates whichdetermine the degree of fineness of the grind.

Fig. 4 is a schematic view in a fiat plane of the arrangement of therespective series of hammers.

In the drawings the base or platform upon which the mill is supported isshown at 10. Secured thereto and extending upwardly therefrom are thetwo spaced bearing supports 11 and 12 which at their upperv ends mountthe bearings 13 and 14. Suitably journalled in the bearings is thedriven shaft 15 which as will readily be observed from Fig. l is twicereduced in diameter at each end at 16 and 17 respectively. The shaft isconnected to a crown type drive pulley 18 about which may be trained inthe conventional manner a belt that is driven by a motor. If desired theshaft may be connected direct to the motor driving shaft. 7 Neither thebelt nor the motor is shown since they are of conventional form and donot constitute a part of the invention.

The mill housing or hopper is shown generally at 19, it defining theannular grinding chamber 2%. The material to be ground is fed into thechamber through the inlet opening 21 that is defined by the upwardlyinclined portion 22 of the housing. An end plate 23 is secured to theadjacent portion of the housing in any suitable manner such as throughthe bolts 24.

Extending into the inlet opening is a feed table 25 which is hingedlymounted at 26 upon the annular wall 27 of the housing. This table has 2.depending and slotted angle 28 secured thereto by the bolts 29. A brace39 is provided for the table, it being pivotally connected to thehousing at one end 31 and being slidably supported within the slot atits other end. As a consequence of this construction it is apparent thatthe table may be arcuately swung about its hinge connection within arange of desired positions as determined by the character of thematerial placed upon the feed table.

The lower portion of the housing is characterized by the side plates orskirts 32 which are suitably bolted to the adjacent portion of thehousing by the bolts 33. Along one inner side of this lower portionthere extends an inwardly directed guide plate 34 that is secured at itsupper end to the adjacent housing side wall 35. Extending outwardlythrough an opening 36 formed in the lower portion of the end plate 23and secured thereto is the vent 37 which at its upper end mountsrelatively slidahle plates 38 and Si. Each of these plates is aperturedat 4t? and with the manual sliding of plate 39 relative to plate 38 thesize of the vent opening may be varied as desired.

Keyed respectively at 41 to the shaft 16 is a plurality oflongitudinally spaced annular plates 42, each plate being provided withspaced apertures 43 adjacent its periphery. While eight such aperturesare shown in the drawings it is, of course, a matter of some choice asto their exact number. The respective apertures are longitudinallyaligned and. have journalled therein the hammer support rods 44. Theserods may be held in place to prevent longitudinal movement by the cotterpins 45 or other suitable means. Swingably connected to the rods arethree separate series of grinding hammers. The first series 46 of thesehammers are crushing hammers, and are disposed at the inlet end of themill as shown in Fig. l and are characterized by being relatively heavyand by having a relatively wide impact edge. The second series 47 of thehammers are so-called grinding hammers. These are lighter and have anarrower edge than the first series. As will be observed in Figs. 1 and4, the second series is disposed intermediate the ends of the rods. Thethird series 48 are so-called thin cutting hammers and are still lighterin weight. and have an even narrower edge. :This series is mountedadjacent the exhaust or ontlet end of the grinding chamber. I Y 1 Thehammers are preferably-or". reverse type so that upon wear they may bereversed to present their other edge. The hammers of each series arehelically or circumferentially spaced so that their respective paths ofrotation at least abut the path of-rotation of adjacent hammers. Asshown in Fig. 4 this construction and arrangement is such that thematerial is forced progressively from the heavier to the lighterhammers, or to state it another way, from the inlet to the outlet end ofthe mill 7 Mounted in the offset portion 59 in the lower half of themill is the replaceable liner 49 of wear resisting steel that can be.smooth or serrated as desired. It is spaced from inch to inch from thehammer tips, depending on the application and material being processed.

Closing off the outlet end of the chamber 29 is a pair of annular plates51 and 52, one of which is suitably securedas by welding or the like at53 to the housing while the other is rotatably mounted therewithin. Eachplate is provided with angular notches or openings 53:: as shown on theplate in Fig. 3, the material being drawn therethrough into the suctionyoke 54. When it is desired tochange the degree of fineness of thematerial it is necessary only for an operator to move the lever 55 thatis connected to the rotatable plate thereby rotating it relative to theother plate and enlarging or reducing the size of the'openings 56 formedbyboth plates.

The suction yoke is formed in such manner as to clear bearing 14 and isin communication with chamber 57 adjacent chamber 20. The end plate 58along'with the plate 51 defines chamber 57. An opening 59 is formed inthe housing wall that also defines chamber 57, so that the lastmentioned chamber is in communication with the suction yoke. This yokealso is provided with slidable gates 60 which may be manually adjustedto enlarge or reduce the opening 61 formed in the Walls of the yoke.

In order to provide air flow means throughout the respective chambers amotor 62 is provided which drives suction fan 63 having hub 64 connectedto drive shaft 65. In communication with the suction fan houshig 66 isthe suction piping 67 which may comprise the desired number of sectionsin order to exhaust the material into the conventional bags orreceptacles. Each section can be coupled as at 63 to its adjacentsection.

In operation the material is first disposed upon the feed table and thenfed into the mill. it is immediately engaged by the so-called crushinghammers and is progressively urged by the respective series of hammerstowards the outlet end of the mill. The grinding operation is of suchcharacter that the material is soon in suspension. As a result of thesuspension grinding and by reason of the fact that the hammers merelystrike the material, the Furthermore, there is a considerable reductionin the heating of the material. Still further, the suspension grindingprevents slugging and power surges.

The progressive movement or advance ofthe material is facilitated asmentioned, by the construction and arrangement of the respective seriesof hammers. Howgrinding is more uniform in character;

ever, the advance or movement is accelerated by the provision of thesuction fan which draws in cool air through the vent 37 and through theinlet opening into which the material is fed. As a result there is aconstant flow of cool air through the grinding chamber as well asthrough chamber 57. As mentioned, this further reduces the heat whichwould otherwise be generated by the grinding operation. 7

When it is desired to vary the degree of fineness of the material it isnecessary only for an operator to move the lever thereby rotating theplate 51 relative to plate 52. The size of the openings formed by bothplates may thus be enlarged or reducedto the required degree; Fur-'thermore, it is unnecessary for the operator tolleave the operatingfloor above the mill, nor is it necessary for the mill to be stopped'orfor any screen to be changed.

In order to assure a greater and more uniform flow of air through thechamber, auxiliary air flow vanes or blades 69 are provided. These areeach-provided With a radius at one end that is complementary to thatofthe adjacent portion of the shaft 15 which the blade abuts. Each bladeis also provided with an aperture 70 through which one of the rods44'extends. The outer extremity 71 of each blade is bent at'an angle sothat as the, shaft 15 rotates the bent portion impinges upon the airinthe chamber and thereby accelerates its movement and flow towards theoutlet. While the number of such auxiliary blades to be employed is amatter of some choice, they.

are always assembled in aligned, pairs for balance purposes (see Fig.2). As is apparent, the blades are mount-.

ed in fixed position and are not characterized by the swinging movementof the previously described hammers.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionand the scope of the claim are also desired to be protected.

The invention claimed is:

' A hammer mill comprising a base, a housing having an inlet and anoutlet supported thereby, a feed table hingedly connected to saidhousing adjacent said inlet and areaately swingable about said hingeconnection within a range of desired inclinations relative to saidinlet, said outlet being defined by a pair of plates having alignedopenings formed therein, one of said plates being fixed to said housingand the other of said plates being rotatably mounted adjacent said oneplate, the other of said plates having an elongated handle projectingbeyond said housing to permit ready rotation of said other platerelative to said one plate to vary the area of the openings of saidoutlet, air flow control means operably associated with said housing fordrawing air from said inlet through said openings, a shaft rotatablymounted in said housing, lon gitudinally spaced members rotatable withsaid shaft, annularly spaced hammer support elements carried by saidmembers, and a plurality of hammers connected to said elements.

References Cited in the file of this patent UNITED STATES PATENTS SalleeApr. 29, 1941

